// 基本数据类型
let user: string = 'Lihua'
console.log(user);
let age: number = 20
console.log(age);
let istrue = true
console.log(istrue);
// null 类型和undefined类型需指定类型
let unl: null = null
let und: undefined = undefined
console.log(unl);
console.log(und);

export{}


